With an increase in the packing density of LSIs, the required linewidths of circuits included in semiconductor devices become finer year by year. To form a desired circuit pattern on a semiconductor device, a method is employed in which a high-precision original pattern (i.e., a mask, or also particularly called reticle, which is used in a stepper or a scanner) formed on quartz is transferred to a wafer in a reduced manner by using a reduced-projection exposure apparatus. The high-precision original pattern is written by using an electron-beam writing apparatus, in which a so-called electron-beam lithography technique is employed.
A writing apparatus using a multi-beam can irradiate with many beams at once, as compared with the case where writing is performed by a single electron beam, thus the throughput can be significantly improved. In a multi beam writing apparatus that uses a blanking aperture array, which is one form of multi beam writing apparatus, for instance, electron beams discharged from an electron gun are passed through a shaping aperture array having multiple openings, and a multi-beam (multiple electron beams) is formed. The multi-beam each passes through a corresponding one of blankers of the blanking aperture array. The blanking aperture array includes an electrode pair for deflecting a beam individually, and an opening for beam passage between the electrode pair, and one of the electrode pair (blanker) is fixed to the ground potential, and blanking deflection is performed individually on a passing electron beam by switching the other electrode between the ground potential and a potential other than the ground potential. An electron beam deflected by a blanker is shielded, and a sample is irradiated with an electron beam not deflected.
In a conventional multi-beam writing apparatus, the path of each beam is slightly curved due to the effect of an electric field which leaks from the blanker of an adjacent beam, a beam irradiation position on the surface of the sample is displaced, and thus the writing accuracy may deteriorate.